POSTHARVEST FRESH COMMODITY QUALITY/PHYTOTOXICITY AFTER ALTERNATIVE MB TREATMENTS

The maintenance of fresh commodity quality is of vital importance to enhance product sale and for successful competition in a global market. Furthermore, the imposition of regulatory quarantine treatments of fresh commodities for pest disinfestation cause injury to the commodities which must be minimized. It is, therefore, essential to develop efficacious quarantine treatments which do not adversely damage fresh commodity quality or increase decay in postharvest storage. Various approaches are been investigated for minimizing quarantine-induced phytotoxicity to fresh commodities. Manipulating the postharvest environment of citrus to enhance the natural resistance to stress by curing/conditioning has shown to lessen peel injury induced by regulatory cold treatments (Houck et al., 1990). Recently, conditioning of lemons at 15EC for 3 days before methyl iodide fumigation lessened lemon peel injury. Conditioning was found to alter soluble sugars changes of the lemon peel which may be involved in moderating stress and protecting cellular membranes (Aung et al., 1998). Additional study is being conducted to evaluate the influence of fruit maturity and origin on treatment effectiveness in order to increase the reliability and general applicability of conditioning in lessening citrus phytotoxicity. We have previously reported (Obenland, 1997) that nectarines apparently tolerate hig